Democrats thought the 2024 election was a contest to see who was the more qualified candidate. It wasn't. The 2024 election was a referendum on "wokeness".
That's why Trump won. The people who elected him do not give one jive that he's terrible, or that he's incompetent, or that he'll run the country into the ground. They believed that by voting for him, they were casting a vote against "wokeness". That was the only thing they cared to know.
Even now, you can easily trigger any group of Trumpers into losing their jive by promoting "wokeness" in their presence.
To be fair, Republicans aren't the only ones who don't understand the concept of an election. Many "progressives" were under the impression that the election was an opportunity to send a message to the Democratic Party about the immorality of sucking Israel's dick, and they used it for that purpose, regardless of the consequences.